JP5201076B2 - Particle manufacturing method and particle manufacturing apparatus - Google Patents

Description

  The present invention relates to a particle manufacturing method and a particle manufacturing apparatus for solidifying droplets to form particles.

  In the formation of toners used in electrophotography, electrostatic printing, and the like typified by ink jet printers, a widely used toner manufacturing process is to use a nozzle from a toner composition liquid containing a resin and a colorant in a solvent. It has a process of forming through droplets and further solidifying. The toner that affects the quality of the printed screen requires a uniform size, so the droplets ejected from the nozzle must maintain a uniform size in the process of forming particles. . Further, not only in the production of toner, but also in the case where particles are formed by solidifying droplets, a technique for realizing particles having a uniform size is required.

  FIG. 1 is a diagram illustrating a conventional toner manufacturing apparatus 100. The toner manufacturing apparatus 100 includes a toner composition liquid storage unit 101, a droplet discharge unit 102, a particle formation unit 103, a toner collection unit 104, and a toner storage unit 105.

  The toner composition liquid storage unit 101 stores a toner composition liquid 106 containing a resin, a colorant, and the like, and the toner composition liquid 106 is supplied to the droplet discharge unit 102 by using the pump 107 or the like.

  A droplet 110 is ejected from a nozzle plate 109 included in the droplet ejection unit 102, and the ejected droplet 110 is transported by a dry gas 111 flowing in the traveling direction (vertical direction) of the droplet in the particle forming unit 103. During the conveyance, the solvent of the droplets 110 is removed, and toner particles P are formed. The toner particles P are collected by the toner collection unit 104 and stored in the toner storage unit 105.

  FIG. 2 is a diagram illustrating a conventional droplet discharge unit 102. 2A is a perspective view, and FIG. 2B is a schematic cross-sectional view. In FIG. 2A, the droplet discharge unit 102 includes a vibration generating unit 21, a housing 22, and a nozzle unit 23.

  When printing in an inkjet printer or the like, or creating granular crystals of molten material, etc., liquid droplets are ejected and dropped into a gas to remove the solvent, etc., or form solidified particles by solidification when dropped. Drops may be coalesced, that is, a state where droplets collide or adhere to each other to form a single droplet. Several measures have been taken to prevent coalescence of the droplets.

  For example, Patent Document 1 describes a technique for preventing coalescence due to collision between droplets by blowing gas from a lateral direction to a droplet that is falling.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a technique for preventing droplets from being coalesced by vibrating or moving the nozzles when discharging molten metal droplets from the nozzles.

  Further, Patent Document 3 describes a technique for preventing the falling droplets from being coalesced by the three-dimensional movement of a nozzle when producing a granular crystal from droplets melted in a crucible.

  FIG. 3 is a diagram exemplifying the state of coalescence of droplets. The positions of the droplets 32 ejected from the nozzles 31 along the direction 33 of the flow of the dried gas 111 at predetermined times are schematically shown in a single figure. The intervals in the flow direction of the droplets ejected one after the other are narrow, and the drop speed is reduced by the resistance of the gas, for example. In this state, particles are generated.

  In the case of using a droplet discharge frequency at a high level of several tens KHz for the production of particles having high productivity, the interval between droplets discharged before and after is particularly narrow. According to the spraying method, the droplets frequently coalesce and it is difficult to sufficiently prevent the coalescence. Further, it is difficult to cope with high production at a discharge frequency level of several tens of Hz, such as other conventional molten metal droplet discharge. Furthermore, even if the three-dimensional mechanical movement of the droplet discharge nozzle is used, the movement amount of the nozzle becomes an extremely small value on the order of, for example, a micron (μm) due to mechanical constraints. In the formation of particles that require a droplet size, it is difficult to sufficiently prevent the droplets from coalescing.

  The present invention has been made in view of the above, and even when the discharge frequency of the droplet is increased with respect to the discharge droplet of the composition liquid for particle formation, sufficient droplet prevention is achieved. The purpose is to do.

In order to achieve the above object, according to one embodiment of the present invention , there is provided a droplet discharge step for discharging a charged droplet, and a time-varying electric field in the droplet in a direction orthogonal to the traveling direction of the droplet. was allowed to act, possess the droplet dispersion step of dispersing the liquid droplets, the particle formation step of forming a particle by solidifying the liquid droplets, and a particle collection step of collecting the particles, the electric field Are two electric fields formed by two pairs of deflection electrodes, and when the directions of the two electric fields are orthogonal, the voltage applied to the two pairs of deflection electrodes is a function of a sine wave with respect to time. Characterized by a method for producing particles.

  According to the present invention, even when the ejection frequency of the droplet is increased with respect to the ejection droplet of the composition liquid for particle formation, it is possible to sufficiently prevent the droplet from being coalesced.

1 is a diagram illustrating a conventional toner manufacturing apparatus 100. FIG. It is a figure which illustrates the conventional droplet discharge unit. It is a figure which illustrates the state of uniting of a droplet. It is a figure which illustrates the process of the toner manufacturing method which concerns on the 1st Embodiment of this invention. It is a figure which illustrates the toner manufacturing apparatus 50 which concerns on this invention. It is a figure which illustrates about Coulomb force, initial velocity, a position, etc. which a droplet receives when passing an electric field. It is a figure which illustrates the waveform of the voltage applied to the deflection | deviation electrode which concerns on this invention. It is a figure which illustrates the combination of two deflection electrode pairs and one discharge nozzle which concern on the 2nd Embodiment of this invention. It is a figure which illustrates the value of electric field E1, E2 and the intensity | strength of an electric field which concern on the 2nd Embodiment of this invention. It is a figure which shows typically the behavior of the three droplets discharged continuously based on the 2nd Embodiment of this invention. It is a figure which illustrates typically the state in the particle formation process of the droplet group discharged continuously from the nozzle N based on the 2nd Embodiment of this invention. It is a figure which illustrates other electric field E1, E2, and the intensity | strength of an electric field based on the 2nd Embodiment of this invention. It is a figure which illustrates the intensity | strength of the other electric field based on the 2nd Embodiment of this invention. It is a figure which illustrates the value of electric field E1, E2 and the intensity | strength of an electric field which concern on the 3rd Embodiment of this invention. It is a figure which illustrates the electric field E1, E2 and the intensity | strength of an electric field based on the modification of the 3rd Embodiment of this invention. It is a figure which illustrates the droplet discharge unit which has the charging mechanism for charging the discharge droplet based on the 4th Embodiment of this invention. It is a figure which illustrates the toner manufacturing apparatus 170 which concerns on the 5th Embodiment of this invention.

Hereinafter, embodiments will be described with reference to the drawings.
<First Embodiment>
FIG. 4 is a diagram illustrating the steps of the toner manufacturing method according to the first embodiment of the invention.
The steps include a droplet discharge step (S101), a droplet dispersion step (S102), a particle formation step (S103), and a particle collection step (S104).

The above process will be described with reference to the toner manufacturing apparatus 50 according to the present invention shown in FIG. The toner manufacturing apparatus 50 includes a droplet discharge unit 51, a deflection electrode 52, a particle forming unit 53, a particle collecting unit 54, and the like.
(S101: Droplet ejection process)
The toner composition liquid 55 is discharged as droplets D from the nozzles 58 arranged on the nozzle plate 57 by driving the vibration of the vibration generating unit 56 in the droplet discharge unit 51. Since the toner composition liquid droplets D have a property of being easily charged, they are easily charged when they pass through the nozzle or due to friction with the gas in the atmosphere.
(S102: Droplet dispersion step)
The discharged charged droplets D are subjected to a Coulomb force by the electric field E of the deflection electrode 52 provided immediately after the nozzle plate 57, and prevent the coalescence of the discharged droplets before and after each other, as will be described later. Therefore, the traveling direction is dispersed, and the positions after dropping are dispersed.
(S103: Particle formation step)
The droplets D are removed in the particle forming unit 53 by the dry gas flow 59 flowing in the same direction as the traveling direction (vertical direction), and the solvent is removed to form toner particles P. The In the particle forming unit 53, due to the effect of droplet dispersion by the above-described droplet dispersion step, coalescence between adjacent droplets or toner particles after solidification is prevented and dispersed.
(S104: Particle collection step)
The formed toner particles P are collected in the particle collecting unit 54. Then, it is transferred to the downstream particle reservoir 61 by the operation of the suction pump 60.
(Drop dispersion method)
Hereinafter, a dispersion method for preventing coalescence of droplets of successive toner composition liquids in the particle forming process will be described.

  By passing the electric field generated by the deflection electrode to the charged droplet of the toner composition liquid and applying the Coulomb force from the electric field, the initial velocity is applied to the droplet in the direction of the electric field strength at the time of passage of the deflection electrode. give. The trajectory of the progress of the droplet in the particle forming unit is determined according to the initial velocity obtained in the direction of the electric field and the flow velocity of the conveyed gas. Therefore, the voltage applied to the deflection electrode that forms the electric field can be changed with respect to time t, and the initial velocity can be changed to achieve the dispersion of the droplets.

  FIG. 6 exemplifies the Coulomb force received when the droplet passes through the field of the electric field E (t) in the direction perpendicular to the traveling direction G of the droplet immediately after being ejected by the nozzle, the initial velocity, the position change, and the like. FIG. The electric field E (t) is generated by the deflection electrode 52 and changes with time t.

For the electric field E (t), when the applied voltage to the deflection electrode is, for example, a sine wave A · sin (2πp × t−φ), the charged liquid droplet D of the charge q is in the direction of the electric field.
F = q × A · sin (2πp × t−φ) (Expression 1).
Receiving the coulomb force.

  FIG. 6A shows the Coulomb force F1 and initial velocity v1 that the droplet D1 discharged from the nozzle N1 receives at time t1. FIG. 6B shows the Coulomb force F2 and initial velocity v2 that the droplet D2 discharged immediately after the droplet D1 is discharged at time t2.

  Since the difference between the initial velocities v1 and v2 of the droplets D1 and D2 occurs according to the Coulomb force (Equation 1) received at the times t1 and t2 when the respective droplets pass through the electric field, the values of (Equation 1) are different. In some cases, the droplets D1 and D2 rarely overlap in the direction of the electric field, and may collide or catch up in the traveling direction (generally in the vertical direction and perpendicular to the electric field direction). Is low.

  FIG. 6C is a diagram illustrating the positions of M consecutive droplets in the particle forming unit at time tM. That is, when the droplets D1, D2,..., DM pass through the deflecting electrode 52 at times t1, t2,. It is the figure which illustrated the position of particle | grains. Each droplet receives a Coulomb force proportional to the strength of the electric field and obtains an initial velocity in the direction of the electric field, so when observing a droplet in a virtual plane including the direction of the electric field and the traveling direction of the droplet, The droplet is generally in a position that exhibits a sine wave.

  FIG. 6D shows an overview of a collection of trajectories of each droplet (or solidified particle) on a plane orthogonal to the traveling direction (a cut surface taken along the line XX in FIG. 6C). It is a schematic diagram. Since the nozzles for discharging the droplets are arranged in a grid pattern on the plane, the entire droplets discharged at the lattice point at the same time move in the direction of the electric field by the Coulomb force received from the electric field, When the states at a certain time are overlapped, the lines as shown in the figure centering on the positions of the lines J1, J2,..., Jk corresponding to the nozzles forming the k rows in the width direction constituting the nozzle plate. A trajectory of dispersed droplets or particles with a width can be observed.

7 shows the voltages applied to the deflection electrode 52 as follows: (a) sine wave (amplitude A, frequency p, initial phase φ), (b) triangular wave (amplitude a, period T), and (c) trapezoidal wave (amplitude b). FIG. 3 is a diagram illustrating a cycle S). The shape of the periodic function is desirable for handling the signal. In addition, when the applied voltage is a triangular wave, the intensity of the electric field also changes at the apex of the triangular wave, but in the case of a sine wave, the electric field is at the apex of the wave (a portion whose phase is an odd multiple of π / 2). Since the change in intensity is minimal, the triangular wave may have a higher effect of preventing droplet coalescence at a corresponding location. However, as described below, by controlling the frequency of the applied voltage having a predetermined relationship with the ejection frequency, even when the change in the electric field strength is minimal, droplet coalescence can be prevented appropriately. it can.
(Droplet discharge frequency and applied voltage frequency)
When the frequency of the voltage applied to the deflection electrode and the frequency of droplet ejection have a harmonic or sub-harmonic relationship, the possibility of unity of the droplets increases. The reason is that the waveforms of the two frequencies of applied voltage and droplet ejection are synchronized, so that the droplets ejected at a predetermined time interval fall (positions on a virtual plane perpendicular to the traveling direction). This is because there is an increase in overlapping.

  Here, harmonics means a signal having a frequency component that is an integral multiple of the fundamental wave, and sub harmonics means a signal having a frequency component that is a fraction of an integer of the fundamental wave. ing.

Therefore, in order to produce a uniform toner, the relationship between the ejection frequency and the frequency of the voltage applied to the deflection electrode is different for both harmonics and subharmonics, that is, an integer multiple or a fraction of an integer. By setting no frequency, coalescence of droplets or toner can be prevented. Even in the case of discharging a high-frequency droplet for improving the productivity of the toner, it is possible to easily prevent the droplets from being coalesced by controlling the voltage applied to the deflection electrode.
(Effects of the first embodiment)
By changing the voltage applied to the deflection electrode to disperse the paths in the particle formation process of the droplets, the droplets can be prevented from coalescing, and high quality toner can be supplied.

  In addition, since the droplets are dispersed using the change in the electric field, no mechanical vibration is caused in the nozzle portion, and dispersion of droplets requiring a high frequency can be easily performed by controlling the change in applied voltage. be able to. In addition, since the strength of the electric field formed by the deflection electrode is uniform, the behavior and trajectory of the droplets ejected simultaneously from multiple nozzles are also in the same direction and uniform, preventing the droplets from coalescing. can do.

  Further, by providing the deflection electrode so as to surround the nozzle, the dried gas does not directly hit the vicinity of the nozzle, and accordingly, the droplet discharge portion of the nozzle is dried or a solid is attached. A good discharge state can be maintained for a long time without causing a defect in the droplet discharge state, and high productivity can be realized.

Furthermore, when the waveform of the applied voltage is a sine wave, an inexpensive waveform generator can be used, and the production cost can be reduced.
<Second Embodiment>
The invention according to the second embodiment of the present invention is provided with deflection electrodes that form two orthogonal electric fields, and controls the Coulomb force acting on the droplets in a two-dimensional plane to prevent the droplets from coalescing. Thus, this is a toner manufacturing method for obtaining a higher quality toner.

FIG. 8 is a diagram illustrating a combination of two deflection electrode pairs 81-81 and 82-82 and one discharge nozzle N2. The deflection electrode pair 81-81 forms an electric field E1, and the deflection electrode pair 82-82 forms an electric field E2. The directions of the electric fields E1 and E2 are orthogonal to each other, and each direction is orthogonal to the droplet traveling direction G. ing. However, each direction can be appropriately adjusted according to the behavior of the liquid droplets or the conditions of the equipment.
(In the case of an electric field with the same frequency and a phase difference of 90 degrees (π / 2))
The voltages V ₁ and V _{2 at} time t applied to the deflection electrode pair 81-81 and the other deflection electrode pair 82-82 are respectively sine waves;
V ₁ = B · sin (2πp ₁ × t−φ ₁ ) (Expression 2),
V ₂ = C · sin (2πp ₂ × t−φ ₂ ) (Expression 3).
(B and C are amplitudes, p ₁ and p ₂ are frequencies, and φ ₁ and φ ₂ are initial phases).

Here, in (Expression 2) and (Expression 3), the amplitudes B and C are set equal to B, the frequencies p ₁ and p ₂ are set equal to p _1, and φ ₁ = 0 and φ ₂ = π / 2 are set. Then, V ₁ and V ₂ are
V ₁ = B · sin (2πp ₁ × t),
V ₂ = −B · cos (2πp ₁ × t).
Therefore, the intensity of the electric field obtained by synthesizing the electric fields E1 and E2 is represented by a circle.

9, the amplitude B, when the difference between the frequencies p ₁ and the initial phase is 90 degrees (π / 2), a diagram illustrates the synthesis of the intensity of the electric field E1, E2 and field. 9A shows a sine wave having the intensity of the electric field E1, FIG. 9B shows a sine wave having the intensity of the electric field E2, and FIG. 9C shows a synthesized electric field in the E1-E2 plane. Indicates strength. In FIG. 9C, a point indicating the electric field strength with respect to time t is represented as E (t), and a point indicating the electric field strength at time t = 1 / 4p ₁ is represented as E (1 / 4p ₁ ). Yes. In FIG. 9, since the difference between the same frequency, the same amplitude B, and the initial phase is π / 2, the strength of the combined electric field is always constant at B, and the direction of the electric field is opposite to the value of the angular velocity 2πp _1. Rotate clockwise.

For example, the intensity of the electric field at time t = 3 / 8p ₁ is the length of the arrow OE (3 / 8p ₁ ), that is, B, and the direction is an intermediate angle between OE1 and OE2 (counterclockwise 45 from OE1). Direction). Accordingly, a droplet having a charge q receives a Coulomb force of size q × B in the direction of an arrow OE (3 / 8p ₁ ), obtains an initial velocity v0, is transported to a dry gas, and drops. .
(Droplet behavior)
FIG. 10 is a diagram schematically showing the behavior of the three droplets R1, R2, and R3 ejected continuously from the nozzle N1 at times t1, t2, and t3.

  The droplet R1 ejected at time t1 obtains an initial velocity v10 in the direction of H1 in which two orthogonal electric fields are combined, and at time t3 when the droplet R3 is ejected, the electric field direction (horizontal direction). Although it is moving by a distance of approximately v10 × (t3−t1), it jumps to the position of R13 in the figure by the gas flow 59 in the vertical direction. The droplet R1 travels while drawing almost a parabola in the plane PL1 formed by the direction of the electric field H1 and the direction of the gas flow 59. Since the droplet receives a resistance force from the gas, it eventually proceeds in the direction of the gas flow 59.

The droplet R2 ejected at time t2 obtains an initial velocity v20 in the direction H2 of the electric field, and moves at a distance v20 × (t3−t2) in the direction of the electric field at time t3. , Fly to the position of R23 in the figure. At this time, the droplet R2 draws almost a parabola in the plane PL2 formed by the direction H2 of the electric field and the direction of the gas flow 59, and eventually proceeds in the direction of the gas flow. An angle θ12 formed by the planes PL1 and PL2 is an angle 2πp ₁ × (t2−t1) formed by the direction of the electric field at times t1 and t2.

Similarly, the droplet R3 ejected at time t3 obtains an initial velocity v30 in the direction H3 of the electric field, and draws a parabola almost in the plane PL3 formed by the direction H3 of the electric field and the direction of the gas flow 59. Fall.
An angle θ23 formed by the planes PL2 and PL3 is an angle 2πp ₁ × (t3−t2) formed by the direction of the electric field at times t2 and t3.
(Track of droplet group)
FIG. 11 is a diagram schematically illustrating a state in a particle forming process at a certain time of a droplet group continuously ejected from the nozzle N. FIG. 11A is a perspective view, and FIG. 11B is a diagram in which droplet groups are viewed in the direction G of droplets ejected from the nozzle. The droplets R10, R11, R12,... In FIG. 11 are continuously ejected droplets, and the initial velocity is obtained from the electric field strength in FIG. The fall is progressing. The direction of the arrow of the drop progression corresponds to the direction of the tangent of each parabola in FIG. In addition, in order to express the positional relationship of each droplet, a broken line spiral or the like is shown as an auxiliary line in FIG. Further, if the droplet group (R10, R11, R12,...) Is observed from the direction G of the droplet discharged from the nozzle N, the droplet group forms a circle, and the time The circle will expand. In the region 11A immediately after passing the electric field in FIG. 11A, the circle expands, but the droplet gradually advances in the direction of the gas flow 59 due to the resistance force that the droplet receives from the gas. Thus, in the region 11B, the droplet group proceeds in the direction of the gas flow 59, so that the trajectory of the entire droplet is maintained in the shape of a circle having the same diameter.

FIG. 11B shows a circle C _S indicating the position of each droplet immediately after passing the electric field in the region 11A, a state of an expanding circle, and a circle _{CE having the} same diameter in the region 11B.

  In addition, the behavior of the above-mentioned droplet is the case of a droplet by ejection of one nozzle N. However, since the droplet ejection nozzles are arranged in a grid pattern on a plane, the number of nozzles at the time of ejection is The same number of droplets are discharged at the same time, but the plurality of droplets are rarely united with each other, and uniting can be prevented.

The reason why this unity can be prevented is that the electric field formed is substantially uniform between the deflection electrodes, and even if a plurality of droplets are ejected from a plurality of nozzles at the same time, each droplet is uniform. This is because, within the electric field, the same initial velocity is obtained to move in the same direction, and the same behavior and locus are exhibited while maintaining a predetermined distance from each other. Accordingly, the droplet group is dispersed as a whole, and no coalescence occurs, and a toner having a uniform particle diameter is formed through the particle forming step.
(In the case of electric fields with different frequencies)
FIG. 12 is a diagram illustrating the electric field strength for two electric fields having two frequencies in which the frequency of one applied voltage is twice that of the other applied voltage and the initial phase difference is π / 3.

The applied voltages V ₃ and V ₄ are
V ₃ = C1 · sin (2πp ₂ × t),
V ₄ = C1 · sin (4πp ₂ × t−π / 3).
It is.

  12A shows the electric field E1, FIG. 12B shows the electric field E2, and FIG. 12C shows the intensity of the combined electric field in the E1-E2 plane.

  The electric field strength shown in FIG. 12C is a Lissajous figure. Unlike the case of the same frequency and the initial phase difference π / 2 in FIG. 9 described above, the strength and direction of the electric field change greatly with time. The strength of the electric field varies within a range of values approximately 1.4 times or less of C2. In the Lissajous figure of the E1-E2 plane of the electric field, no electric field is generated in the counterclockwise direction from the E1 axis and at an angle of approximately π / 4 to 3π / 4. Accordingly, the electric field shown in FIG. 12 can be effectively used when the movement of the toner in the toner particle forming process needs to be regulated in the horizontal direction.

  If the entire droplet group in the particle forming step is observed from the direction G of the droplet, as in the description in FIG. 11, the Lissajous figure in FIG. 12C is generally observed as an enlarged figure. The

  FIG. 13 is a diagram illustrating the strength of an electric field by two electric fields when the frequency of one applied voltage is three times the other and the difference in initial phase is π / 3.

The applied voltages V ₅ and V ₆ are
V ₅ = C2 · sin (2πp ₃ × t),
V ₆ = C2 · sin (6πp ₃ × t−π / 3).
It is.

  In the Lissajous figure of FIG. 13, the intensity and direction of the electric field are greatly changed compared to the figure of the electric field intensity of FIG. The intensity of the electric field generally changes in the range of (0.3 to 1.4) times C2. In the particle forming step, the electric field in FIG. 13 can be effectively used when the positional relationship between the droplets or toners that follow each other needs to be further changed.

  In the case of FIG. 13 as well, as in FIG. 11, if the entire droplet group in the particle formation step is observed from the direction G of the droplet, the Lissajous figure in FIG. Is done.

In addition, the waveform of the voltage applied to the deflection electrode is not limited to one sine function, and a plurality of sine functions can be appropriately selected and superimposed to easily generate a desired function shape. In this manner, various functions can be generated and applied as voltage waveforms in accordance with materials such as droplets, other designs, and manufacturing conditions.
(Effect of the second embodiment)
In the particle formation process, the intensity change in the two-dimensional plane of the electric field formed by the two pairs of deflection electrodes is set with a wide degree of freedom even at a high frequency, and the droplets or particles are prevented from coalescing. The particles can be dispersed after dropping, and the formed particles can be made uniform and the quality can be improved.
<Third Embodiment>
FIG. 14 is a diagram exemplifying electric field E1, E2 and electric field intensity values according to a triangular wave applied voltage according to the third embodiment of the present invention.

FIGS. 14A and 14B show the strengths of the electric fields E1 and E2. The periods of the electric fields E1 and E2 are T ₁ , the amplitude is c, and the initial phase is 1 / 4T ₁ in the electric field E2. FIG. 14C shows the strength of the combined electric field in the E1-E2 plane. The combined electric field strength diagram is a square with one side approximately 1.4 times as long as c. Each side of the square forms an angle of 45 degrees with the direction of the electric fields E1, E2. In addition, the electric field strength generally varies in the range of (0.7 to 1) times c.
(Track of droplet group)
As in the case described with reference to FIG. 11, if the entire droplet group in the particle forming step is observed from the direction G of the droplet discharged from the nozzle N, the droplet group forms a substantially square electric field strength. However, the shape expands with time. However, the gas flow becomes a square having the same size in a region where the initial velocity of the droplet is negligible. Each side of the square forms 45 degrees with the direction of each electric field.
(Effect of the third embodiment)
The droplets continuously discharged from each nozzle are dispersed in a square shape as seen from the direction of discharge from the nozzle, so that the droplets do not coalesce, Uniform solidified particles can be obtained.
<Modification of Third Embodiment>
FIG. 15 is a diagram illustrating values of electric fields E1 and E2 and electric field strength according to a trapezoidal wave applied voltage according to a modification of the third embodiment of the present invention.

15A and 15B show the strengths of the electric fields E1 and E2. The periods of the electric fields E1 and E2 are S ₁ , the amplitude is d, and the initial phase is ¼ S ₁ in the electric field E2. FIG. 15C shows the intensity of the combined electric field in the E1-E2 plane. The combined electric field intensity graphic is a square with a side of 2d. The intensity of the electric field generally changes in the range of (1 to 1.4) times c. Note that the squares in the case of the third embodiment are in a positional relationship obtained by rotating 45 degrees.
(Effects of Modification of Third Embodiment)
Similar to the effect of the third embodiment, the droplets continuously ejected from each nozzle are dispersed so that the entire droplet has a square shape when viewed from the direction of ejection from the nozzle. . In addition, uniform solidified particles can be obtained without causing coalescence of droplets.
<Fourth embodiment>
The fourth embodiment of the present invention is a droplet discharge unit having a charging mechanism for charging discharged droplets.

  The electrical properties of the toner are strong because OPC (Organic Photo Conductors: an organic photoconductor in which the photosensitive layer is composed of an organic photoconductive material and a resin) that uses the charged static electricity. Has chargeability. Therefore, normally, when the droplet of the toner composition liquid is discharged, the droplet is charged by friction with the nozzle itself or by friction with the gas in the atmosphere when passing through the nozzle hole. . The droplets discharged and charged continuously before and after the phase are subjected to Coulomb force from the electric field formed by the deflection electrode, and proceed with an initial velocity in different directions as the electric field strength changes with time. Therefore, dispersion can be performed effectively without causing coalescence of droplets and solidified toner.

  In addition, it is possible to strengthen the Coulomb force applied to the droplet from the electric field by forcibly charging the droplet or controlling the amount of charge without relying only on the natural charge on the droplet, thereby forming particles. In this case, droplets and toner can be controlled, and uniform toner formation can be performed.

  FIG. 16 is a diagram illustrating a droplet discharge unit 161 having a charging mechanism for charging discharged droplets of the toner composition liquid according to the fourth embodiment of the present invention.

The applied voltage is set to DC, and the potential of the nozzle plate 57, the housing 162 holding the nozzle plate 57 or the liquid reservoir 62 is maintained at a predetermined positive value with respect to the ground potential, for example. A sufficient amount of charge can be secured.
(Effect of the fourth embodiment)
The charge amount of the discharged droplet can be stabilized to a sufficiently high value, and the droplet is given a strong coulomb force from the electric field of the deflection electrode, giving an initial velocity at which the droplet can be widely dispersed in the particle forming section. Therefore, it is possible to more stably prevent the droplets from being coalesced, and to supply high-quality toner.
<Fifth embodiment>
The fifth embodiment according to the present invention relates to a toner manufacturing apparatus that disperses droplets by applying a Coulomb force to the droplets using an electric field of a deflection electrode that changes with time.

  FIG. 17 is a diagram illustrating a toner manufacturing apparatus 170 according to the present invention. The toner manufacturing apparatus 170 includes a droplet discharge unit 161, a deflection electrode 52, a particle forming unit 53, a particle collecting unit 54, and the like.

  The droplet discharge unit 161 includes a vibration generating unit 56, a liquid storage unit 62 for storing a toner composition liquid 55 supplied from an upper toner composition liquid storage unit (not shown), a nozzle plate 57 having a plurality of nozzles 58, and the like. have.

  For example, a plurality of nozzles 58 are formed with a diameter of 10 μm and a pitch of 200 μm.

  The droplet discharge unit 161 is further provided with the charging mechanism shown in the above <fourth embodiment>.

  The droplets D are periodically discharged from the plurality of nozzles 58 of the nozzle plate 57 by the vibration of the vibration generating unit 56.

  The vibration generating unit 56 includes, for example, a laminated piezo actuator 56a and a vibration propagation unit 56b that uniformly propagates the generated vibration to a wide vibration surface. The vibration generating unit 56 is fixed to the housing 162 and faces the nozzle 58, and the distance from the discharge surface of the nozzle plate 57 is appropriately adjusted by the housing 162 and the like.

  The dimensions of the vibration surface of the vibration propagation portion 56b are, for example, 10 mm in length and 65 mm in width, which are very large values compared to the dimensions of the vibration surface used in a general inkjet printer.

  As the droplets D are continuously ejected and pass through the electric field E of the deflection electrode 52, each receives a Coulomb force, obtains an initial velocity in the direction of the electric field E, and the traveling direction is dispersed. The coalescence of droplets can be prevented. As described in detail in the first to third embodiments, the dispersion with the Coulomb force can be controlled with a high degree of freedom according to the situation.

  The droplets D are removed in the particle forming unit 53 by the dry gas flow 59 flowing in the vertical direction, and the solvent and the like are removed to form toner particles P. In the particle forming unit 53, the effect of the initial velocity obtained when the droplet D passes through the electric field E prevents the droplets ejected one after the other or the solidified toner particles from being coalesced and dispersed to each other. .

The formed toner particles P are collected in the particle collection unit 54 and transferred to the downstream particle storage unit 61 by the operation of the suction pump 60.
(Effect of 5th Embodiment)
Since it is not necessary to provide a mechanical vibration device for dispersing the toner, a low-cost facility can be realized.

  In addition, the state of the electric field strength in a two-dimensional plane can be easily set according to the droplet discharge speed, frequency, lot change, other manufacturing conditions, toner design conditions, or other conditions during toner manufacture. Therefore, it is possible to increase the effect of preventing the coalescence of droplets, and it is possible to realize a high toner productivity and a low-cost toner manufacturing apparatus. In particular, even when a high frequency is required for ejecting droplets, the droplets can be uniformly dispersed by controlling the electric field with an applied voltage having a high frequency.

  Furthermore, the quality of the toner using the toner manufacturing apparatus can be improved.

  The preferred embodiment has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various modifications and replacements are made to the above-described embodiment without departing from the scope described in the claims. Can be added.

For example, by providing not less than two pairs of deflection electrodes but three or more pairs, it is possible to further increase the degree of freedom of dispersion of the droplets and further improve the uniformity of the quality of the formed particles.
(Application to fields other than toner)
A technique for forming uniform droplets by preventing the coalescence of droplets is not limited to toner production, and can be used for droplet production methods and droplet production apparatuses in other fields. For example, it can be effectively used in a manufacturing method and apparatus relating to a droplet forming process in a spray coating apparatus, a polymerization apparatus, a display film forming apparatus, an ink jet printer, and an electrode manufacturing apparatus.

21 Vibration generating part 22 Housing 23 Nozzle part 26 Flange 27, 31, 58 Nozzle 28, 57 Nozzle plate 29, 62 Liquid storage part 32 Liquid droplet 33, 59 Gas flow direction 50, 170 Toner production device 51, 161 Liquid droplet Discharge unit 52, 81, 82 Deflection electrode 53 Particle formation part 54 Particle collection part 55 Toner composition liquid 56 Vibration generation part 56a Laminated piezo actuator 56b Vibration propagation part 60 Suction pump 61 Particle storage part 162 Housing D, R Droplet E Electric field N Nozzle F Coulomb force G Droplet traveling direction H1, H2, H3 Direction of combined electric field J Line corresponding to nozzle of entire droplet P Toner particle

Japanese Patent No. 3259305 JP 2000-328111 A JP 2008-50256 A

Claims (8)

A droplet discharge process for discharging charged droplets;
A droplet dispersion step of dispersing the droplets by applying a time-varying electric field in a direction orthogonal to the traveling direction of the droplets to the droplets;
A particle forming step of solidifying the droplets to form particles;
Possess a particle collection step of collecting the particles,
The electric fields are two electric fields formed by two pairs of deflection electrodes;
When the directions of the two electric fields are orthogonal, the voltage applied to the two pairs of deflection electrodes is a function of a sine wave with respect to time.
Particle production method. The difference between the two electric field initial phase of process according to claim 1, wherein the particles characterized in that an odd multiple of 90 degrees ±. A droplet discharge process for discharging charged droplets;
A droplet dispersion step of dispersing the droplets by applying a time-varying electric field in a direction orthogonal to the traveling direction of the droplets to the droplets;
A particle forming step of solidifying the droplets to form particles;
A particle collecting step for collecting the particles,
The electric fields are two electric fields formed by two pairs of deflection electrodes;
When the directions of the two electric fields are orthogonal, the voltage applied to the two pairs of deflection electrodes is a function of a triangular wave or a trapezoidal wave with respect to time .
Particle production method. The method for producing particles according to claim 3, wherein the phase difference of the function of the triangular wave or trapezoidal wave is an odd multiple of ± 90 degrees. The method for producing particles according to any one of claims 1 to 4 , wherein the frequency of the time-varying electric field is different from harmonics or subharmonics of the ejection frequency in the droplet ejection process. . The droplets, the nozzle plate unit of the droplet ejection step, the charging of the housing or the liquid reservoir for holding the nozzle plate, any one of claims 1 to 5, characterized in that it is charged A method for producing the described particles. A droplet discharge unit for discharging charged droplets;
A deflection electrode for dispersing the droplet by applying a time-varying electric field in a direction perpendicular to the traveling direction of the droplet to the droplet;
A particle forming unit that solidifies the droplets to form particles;
Possess a particle collection unit for collecting the particles,
The electric fields are two electric fields formed by two pairs of deflection electrodes;
When the directions of the two electric fields are orthogonal, the voltage applied to the two pairs of deflection electrodes is a function of a sine wave with respect to time.
Particle production equipment. A droplet discharge unit for discharging charged droplets;
A deflection electrode for dispersing the droplet by applying a time-varying electric field in a direction perpendicular to the traveling direction of the droplet to the droplet;
A particle forming unit that solidifies the droplets to form particles;
A particle collecting part for collecting the particles,
The electric fields are two electric fields formed by two pairs of deflection electrodes;
When the directions of the two electric fields are orthogonal, the voltage applied to the two pairs of deflection electrodes is a function of a triangular wave or a trapezoidal wave with respect to time.
Particle production equipment.

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